In micro controller units (MCUs) suitable for power conversion applications in which a real-time property is important, such as control of digital power supplies or automobile motors handles various events. For example, conversion ending events are output from analog/digital (A/D) converters, inversion detection events are output from comparators, timing events are output from pulse width modulation (PWM) timers, and arithmetic ending events are output from digital signal processors (DSPs), then control contents are changed according to such events.
JP-A-H09-91139 discloses a technology for correcting an error of a read-only memory (ROM).